by Dr. Jerilynn C. Prior, Scientific Director, Centre for Menstrual Cycle and Ovulation Research
Our primary goal when choosing a reversible birth control method is that it effectively prevent pregnancy, is without personal unwanted side-effects and is affordable and convenient. CeMCOR believes we should add a second goal—that the effective/safe chosen contraceptive method also preserves normal menstrual cycles and ovulation.
These two contraception goals, taken separately, suggest two different ways of looking at the menstrual cycle:
1) The menstrual cycle as the “cause” of fertility, therefore it is useful only for reproduction and is an inconvenience for women who are not ready or willing to have children.
2) The menstrual cycle as the source of balanced, health-producing estrogen and progesterone levels as well as necessary for fertility.
Making a contraceptive choice that is effective, safe and convenient without concern about whether it disrupts the menstrual cycle and ovulation fits with the first concept of menstrual cycles. Preferring a contraceptive method that preserves menstrual cycles and ovulation as well as being effective, safe and convenient accommodates both contraceptive goals and acknowledges the innovative view that normal cycles and ovulation are needed for our lifelong health.
Why should contraception preserve normal cycles and ovulation?
When our bodies make regular, normal-length menstrual cycles with normal egg release (ovulation) and luteal phase lengths weare healthy in body, mind and soul. Illness, not eating enough for our energy needs, angst or abuse are the common causes of adaptive disturbances of cycles/ovulation1. Plus, normal-length, ovulatory cycles provide a healthy balance of estrogen and progesterone that together promote current fertility and bone balance2 as well protecting future heart3, breast4;5 and whole health. Thus ovulatory cycles are both an indicator and a creator of good health.
Is it possible to achieve reversible contraception and preserve cycles/ovulation?
Yes. There are now three available contraceptive methods that preserve menstrual cycles and ovulation; the third is newly documented to be suitable for all women including teens:
1) A barrier (condom, diaphragm or cervical cap) plus vaginal spermicide;
2) Fertility awareness-based methods that include observing and charting signs of fertility including cervical mucus, basal body temperature and, sometimes, cervical position can be highly effective at preventing pregnancy6.
These first two non-hormonal methods, however, are not considered suitable for teenagers who are assumed to have insufficient attention and patience to successfully manage them; also, neither of these methods is considered as effective as hormonal forms of contraception. The good news is we can now add a third reversible, highly effective, non-hormonal contraceptive to the two above:
3) The copper-releasing intrauterine device (Cu-IUD) is highly effective and can be effectively used for contraception even by teens and women who are nulliparous7;8 . The Cu-IUD provides long-acting effective contraception while preserving cycles and ovulation. It is also an effective emergency contraceptive9. The World Health Organization has created a chart that shows reasons to use, or reasons for caution in use, of various contraceptives including hormonal contraceptives such as combined hormonal contraception CHC (that includes the patch and vaginal ring but is here called “combined oral contraceptive” or COC), Depo-Provera® and the Cu-IUD http://www.who.int/reproductive-health/family_planning/guidelines.htm. You will notice that the Cu-IUD is almost always safe and effective (as shown by light or dark green shading).
In summary—the copper IUD is a highly effective, safe, convenient and long-lasting form of non-hormonal contraception that, except for increasing menstrual cramps (especially in teens)8 is without serious adverse effects. Increased menstrual cramps can be easily managed with the proper use of ibuprofen as discussed in the CeMCOR resource, http://www.cemcor.ca/resources/painful-periods.
Why can’t I be like my friends and use the Pill/CHC?
Hormonal contraception was originally only “the Pill” and now includes combined hormonal contraception [CHC] that is a pill, patch or vaginal ring; DepoProvera® injections every three months; a hormonal insert that is not available in Canada; and the progestin-releasing IUD, Mirena® or Skyla® https://www.arhp.org/publications-and-resources/clinical-fact-sheets/the-facts-about-intrauterine-contraception. Hormonal contraception must disrupt normal reproductive function to be effective. Hormonal contraception suppresses or alters the normal reproductive system at one or more of its important parts: hypothalamus and pituitary (in the brain), ovary, uterus or cervix. Current CHC relies on high dose synthetic estrogen and progestin to suppress the brain's stimulation of the ovary to prevent ovulation. The progestin component in CHC also thins the endometrial lining of the uterus (the reason some may have lighter flow when using these methods) and dries out the cervical mucus needed to assist sperm in traveling upward for fertilization. Although we call the hormones in the current Pills “low dose,” that is only compared with the first mega-high dose pills from the 1960s. To be effective at preventing pregnancy, the doses of estrogen and progestin in CHC have to be high enough to (usually) suppress the brain, pituitary gland and ovary production of hormones. Compared to average estrogen and progesterone levels during the normal menstrual cycle, current CHC including ethinyl estradiol doses of 20-30 micrograms deliver 4 times the estrogen effect and about the same progesterone actions as in an ovulatory menstrual cycle. The exception to this is the recently introduced “LoLo®” CHC pill that has only 10 micrograms of ethinyl estradiol and a higher, 1 mg dose of a male-hormone derived progestin called norethindrone.
For reasons of tradition, and because the previous CHC progestins were all derived from male hormones and had negative effects on cholesterol, the amount of progestin in the modern CHC is controlled to be relatively less high than the estrogen. Progestins also make the uterine lining too thin for a fertilized egg to hold on and grow, and dry up cervical mucus. In a normal menstrual cycle, estrogen levels rise to a peak in mid-cycle, causing the cervix glands to make slippery clear mucus that helps sperm swim upward to fertilize an egg, or to keep it alive until an egg is released. Progesterone and progestins in CHC both inhibit the actions of estrogen on cervical mucus. Therefore, there are successful forms of contraception that contain only a progestin, including a daily low-dose (0.35 mg) norethindrone pill (so called “mini-Pill”), emergency contraception methods (such as “Plan B”), a progestin-only injection with medroxyprogesterone (Depo-Provera®), and a progestin-releasing IUD (Mirena® and Skyla®). There is no estrogen-only hormonal form of contraception because it would not be effective and would cause severe nausea and breast tenderness as well as an unacceptable risk for endometrial cancer.
Are there serious risks from use of CHC/the Pill?
Although we think of the Pill/CHC as safe, a 25-year observational study in over 45,000 British women, of whom half had used the Pill and half had not, showed that deaths from cancer of the cervix and from cardiovascular diseases (like blood clots, strokes and heart attacks) were significantly increased in women taking CHC or who had used it within the last 10 years10. (When that study started, the estrogen dose was about 5 times higher than is usual today; when it ended, Pill estrogen doses were in the 20-30 ethinyl estradiol range common in many of today’s brands.) However, the overall death rate was similar between those who had ever used and those who had never used the Pill because it caused fewer deaths from ovarian cancer10.
A recent meta-analysis of all studies since 1980 of cardiovascular and blood vessel diseases occurring during current 21-day CHC use showed that even use of the lowest dose CHC was related to a doubling of the risk for strokes and heart attack11(that are admittedly quite low at that age). A study of young women ages 18-49 who had experienced a heart attack (called cases) compared with matched women from the general population (called controls) has shown that even the lowest estrogen dose Pills (before LoLoÒ) still was associated with an increased risk of strokes12. Heart attacks tend to be less frequent in users of CHC that contain progestins not derived from male hormones12.
To put the health risks from CHC use into practical guidelines, here are some recommendations. Those considering use of the Pill/CHC should absolutely not take it if you have a family or personal history of abnormal blood clotting or thrombophlebitis, are actively ill with hepatitis or mononucleosis (viral diseases of the liver that estrogen may make worse), have had breast or endometrial cancer, or are allergic to the hormones in CHC. Pill use carries increased risks if you have a family history of breast cancer, are overweight (BMI of 25 or more), currently smoke, have migraine headaches or have anovulatory androgen excess (AAE, sometimes called PCOS — see “Help for Anovulatory Androgen Excess (AAE) — Challenge PCOS!”). All women should have a normal blood pressure, pelvic examination and Pap test before starting on CHC.
Can teens safely use hormonal contraception?
Sexually active teenagers need effective contraception. The health risks are higher than average for pregnant teenagers, for teenaged mothers and for their babies. Also, the potential for life-disruption from an unwanted pregnancy is great for teenaged women who are still developing the skills they need for independent adulthood. Therefore sexually active teens need effective contraception—CeMCOR strongly suggest that form of birth control be one of the three non-hormonal methods described above for these reasons:
- Hormonal methods of contraception may interfere with the maturation of a teenager’s reproductive system. The ovulatory menstrual cycle takes many years to become established13 even though regular periods commonly develop within a year or so of the first menstruation14. The brain control of cycles and ovulation in teens must be allowed to grow up! Because all forms of hormonal contraception are designed to disturb reproduction, it is in the best interest of teenagers’ health to avoid them.
- Current “low-dose” CHC is very likely to fail as contraception if one or more Pills are missed. A Cu-IUD is more effective than the Pill—you don’t have to remember to take it.
- Injection forms of medroxyprogesterone (Depo-Provera®) are also not recommended because they strongly suppress reproduction, although they have less negative bone effects than previously thought http://www.cemcor.ca/resources/depo-provera-use-and-bone-health.
- More importantly, CHC especially in doses of 30 micrograms of ethinyl estradiol or higher, prevents teens from gaining the normal amount of bone they need for peak bone mass15 and lifelong bone health.
For all of these reasons the preferred contraception for a teenager is the Cu-IUD. All teens on Cu-IUD should know how to prevent cramps http://www.cemcor.ubc.ca/resources/painful-periods. All teens needing contraception should know how to access emergency contraception9 as a backup.
Given that today’s doses of hormones in CHC don't entirely suppress ovarian hormone production, and estrogen production is even higher in perimenopause16, theoretically using the Pill in perimenopause would carry both greater risks for contraceptive failure and potentially very high estrogen levels. There are important differences between taking CHC as a young woman and taking it as a perimenopausal woman. We know that estrogen levels rise in perimenopausal women because the normal brain-ovary feedback loops are disrupted with ovarian aging (see “Perimenopause: The Ovary's Frustrating Grand Finale”). We also know that weight tends to increase in perimenopause. We believe that both this abnormal perimenopausal feedback and the weight gain of perimenopause are reasons to avoid CHC use during this time. The risks for clots, strokes and heart attacks also increase as women get older and that these risks are doubled by current use of cigarettes. Therefore, any current smoker should avoid use of CHC.
Sometimes CHC is recommended in perimenopause control of bone loss and treatment of hot flushes as well as birth control. To our knowledge there is only one randomized double blind controlled trial of the Pill for treatment of heavy bleeding; it showed CHC made abnormal menstrual bleeding worse in the first 3 months and only after 6 months caused reduced flow17. This study showed also that CHC did not improve hot flushes or quality of life compared to a placebo17. However, the CHC, if it were safe in perimenopause, might help prevent bone loss in perimenopausal women who with skipped periods18 based on not very scientific (not randomized or placebo-controlled) evidence. Cyclic Progesterone Therapy http://www.cemcor.ca/resources/topics/cyclic-progesterone-therapy may be a better option to preserve perimenopausal bone density and decrease symptoms19.
What about CHC/the Pill and safety for bones and osteoporosis?
We know that estrogen or estrogen with progestin therapy in menopausal women increases bone mineral density (a good thing)20 and prevents fractures21;22. In the past we were sure that CHC use would prevent osteoporosis. However, a random sample of about 550 premenopausal Canadian women ages 25-45 showed that those who had ever used the Pill had lower bone density levels than did women who had never used the Pill23. Also, several studies show that those who used CHC versus not, adjusted for their differences, experienced more fractures as menopausal women24;25 We’ve already discussed the evidence that using CHC prevents teenagers from gaining their full peak bone mass15.
Effective hormonal contraception, especially CHC/the Pill provided a marvelous advance for women in the last five decades. Recently both patch and vaginal ring CHC have become available—these have the potential to decrease the risks for blood clots (and other vascular diseases) that are related to the Pill. We now know that disrupting menstrual cycles and ovulation has negative consequences for women’s lifelong health. Hormonal contraception should be avoided in favour of the copper IUD for teenagers. There are many concerns with CHC use in teenagers, perimenopausal women, overweight women and those who smoke. It a better choice to use available, effective, safe, non-hormonal birth control methods that do not disrupt menstrual cycles/ovulation such as the copper IUD, barrier-plus-vaginal-spermicide, or fertility awareness-based methods. Hormonal contraception requires high doses of synthetic hormones, disrupts our own menstrual cycle/ovulation and deprives us of the health benefits that come with consistent ovulation http://www.cemcor.ca/resources/preventive-powers-ovulation-and-progesterone.
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